Crossbow



Patented Sept. 9, 1952 UNITED STATES PATENT y OFFICE.

CROSSBGW Adolph V. Gruner, Pittsburgh, Pa.

Application January 25, 1949, Serial No. 72,669 2 claims. (c1. 124-25) This invention `relates to improvements in crossbows whereby greater accuracy of aim may be obtained than is ordinarily had in the use of this class of weapons.

One of the objects of the invention is to provide a novel construction or" a bow and improved means for securing the same to the barrel of the crossbow.

Another object of the invention is to provide a novel means to prevent back-lash of the bow member after the projectile has been discharged.

Still another object of the invention is to pro-` vide novel means for tripping or releasing the bow-string without altering the tension of the bow-string when discharging a projectile.

The preferred embodiment of my invention is illustrated in the accompanying drawing, where- Figure 1 is a perspective View of my improved cross-bar, showing the projectile in loaded position.

Figure 2 is a sectional view on line 2-2 in Figure 1.

Figure 3 is an isometric detail view of the bow securing means.

Figure 4 is a section on line 4 4 in Figure 1.

Figure 5 is a reduced fragmentary perspective View of the rigid strip and flexible bow, showing the notches which fit into the slots of the strip and bow securing means.

Figure 6 is a fragmentary perspective view showing in full lines the trigger details when in loaded position and in dot and dash lines, when in discharged position.

Figure '7 is a top view oi the projectile or bolt as used in this invention.

Figure 8 is a sectional view showing the bow and damper in the saw cut of the barrel.

Similar numerals of reference indicate like parts throughout the several views in the drawN ing.

Referring now to the drawing, the particular construction of the crossbow I shown. comprises in general a barrel Il, a stock I2, the bow I3, a trigger mechanism I4 and the projectile or bolt I5.

The combined stock and barrel are preferably made of wood in which the latter is provided along its top edge I with a longitudinal groove or recess Il, extending from the muzzle i8 to a point I9 near the trigger mechanism I4. Groove Il serves to guide the propelled projectile I5. The latter comprises a bullet-shaped body 20, terminating at the front into a pointed head 2l provided with a metallic point 22, and terminating at the rear into a tail 23, consisting of a pair of-spaccd apart stiff feathers 24 `in which the quills 25 are securely inserted. Feathers 24 are preferably arranged and spaced as shown in Fignism I4 in the shape of a vertical vshoulder' 28 which is adapted to retain the bow-string 29 until released by trigger mechanism I 4I. The latter comprises a U-shaped trigger 30 pivotally mounted on a pivot pin 3l in a prepared cavity 32 at a point on the underside of the barrel near the trigger 30. A trigger pin 33, the lower end of which is secured to the bridge-portion of the U-shaped trigger 30, and the upper end of which is` provided with a flat, square head 34, is vertically slidable in a vertical aperture 36. The shank 35 of trigger-pin 33 penetrates freely through the vertical aperture 36.

The trigger mechanism assumes a normal position, as shown in full lines in Figures 2 and 6, by gravity or by means of a coil spring 3l, as shown.

A The bow E 3 is constructed of a single flat piece o f iiexible steel 38 backed up by a flat piece of stiff steel 39, both being secured to the barrel I I, near the muzzle I8, as follows: the flexible bow I3 and the stiff back-up strip or damper 39 are inserted in parallel relation in a prepared sawcut A0 positioned adjacent the muzzle I8 at the underside of the barrel II (Fig. 8) after which slots 43 of the U-shaped bow and damper strip retainer 4I are slipped over both members 39 and I3 until the notches 42 of these members interlock with slots 43 of retainer M. After the bow and damper are in position the retainer 4I is secured to the sides of the barrel l! by screws M, or otherwise.

The top of the saw-cut is protected from wear by means of a narrow metal strip 45 of the same width as the saw-cut which is bent over and forced into the sides of the barrel.

The string 29 is attached to the ends M of the flexible bow I3 in any suitable manner and when it is desired to operate the gun the projectile i5 is placed with its rear portion abutting pin 48 (Fig. 2) located near the trigger end of the groove il on the top edge IS of barrel II.

The trigger 30 is now in normal position (Figure 2) and the string 29 is placed around the shoulder 28, as best shown in Figures 1 and 2. The head 3d of trigger pin 33 is, normally, in a position as shown in Figure 2, either by gravity or by means of a coil spring 3l. The stretched string 29 rests on top of head 34 and by pushing trigger 30 upwardly, the top of head 34 of trigger pin 33 is also moved upwardly thereby causing string 29 to be slipped out of engagement with shoulder 28 over which the string has been stretched. The moment this occurs, the string violently strikes the rear end of the bullet shaped body 2U of the projectile I5, thereby causing the latter to be swiftly propelled forwardly from the bow.

In the crossbar structures of the prior art after the tensioned string has been slipped out of engagement with the shoulder 28 the string always passed over the muzzle I8 and below the barrel Il instead of halting at the bow or only slightly in front of it as shown in dot and dash lines in Figure 1. This has been fully remedied by using a stiff back-up strip or damper 39 which lies in parallel alignment in saw-cut 40 with bow spring 38 and is held therein in the same manner as isthe bow-spring. This arrangement prevents the ends of the bow-spring 38 from vibrating too farforwardly and at the same time prevents the string Vfroin passing the muzzle as it did before a damper strip 39 was applied.

It will thus befseen that I have provided an with a projectile guiding slot therein, a bow member'passing through the barrel at a point adjacent its muzzle and adapted, when relaxed,j

to lie in a plane .perpendicular to the Vertical plane of `said barrel a separate damping member passing through the barrel in a plane parallel to the plane of the bow, said damping member being in contact with the bow at their'mid-points only except when said bow is relaxed or forward of the relaxed'position and adapted to dampen the forward movement of the bow when forward of its normally relaxed position, a U-shaped member tted about the underside of the barrel and slotted to receive the bow and the damping member, a second U-shaped member passing through the barrel above the bow and damping member to protect the barrel from damage by the bow, a bow stringconnecting the ends of the bow, a Vertical shoulder Aadjacent the junction of barrel and stock receiving the bow string when the bow is drawn and releasing means adapted to release the bow string from said shoulder while maintaining substantially constant tension of the bow string until the instant of release.

2. In a crossbow, having a stock and barrel with a projectile guiding groove therein, a bow member passing through the barrel at a point adjacent its muzzle and adapted, when relaxed, to lie in a plane perpendicular to the vertical plane of said barrel and stock, a separate damping member passing through the barrel in a plane parallel to the plane of the bow, said damping member being in contact with the bow at their mid-points only except when said bow is relaxed or forward of the relaxed position and adapted to dampen the forward movement of the bow when forward of its normally relaxed position, a U-shaped member fitted about the underside of the barrel andvslotted'to receive the bow and damping member, a second U-shaped member passing through the barrel above the bow, a bowstring connecting the ends of the bow, a vertical shoulder adjacent the junction of barrel and stock receiving the bow-string when the bow is drawn and releasing means adapted to release the bow-string from said shoulder while maintaining substantially constant tension on the bow-string.

ADOLPH V. GRUNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 28,698 Stevens June 12, 1860 650,411 Myers May 29, 1900 785,050 Saunders Mar. 14, 1905 1,089,713 Liljencrantz Mar. 10, 1914 1,133,189 Shannon Mar. 23, 1915 1,488,149 Cole Mar. 25, 1924 1,704,810 Sperry Mar. 12, 1929 2,278,535 .Dobson Apr. 7, 1942 FOREIGN PATENTS Number Country Date 686,224 France Apr. 8, 1930 276,888 Great Britain Sept. 8, 1927 

